Polyisocyanurate and polyurethane foam, or PUR/PIR foam, is used in applications such as structural walls, roofs, refrigerator cabinets, and garage doors. One challenge faced by PUR/PIR foam formulators and manufacturers is to improve the insulation performance or efficiency of the PUR/PIR foam without increasing the foam thickness. Improving the insulation efficiency of the PUR/PIR foam is beneficial as it improves energy efficiency of the final wall, roof, or other product, and results in less PUR/PIR foam being required in the final product to achieve the desired energy efficiency.
Another challenge faced by PUR/PIR foam formulators and manufacturers is to increase the rate of production of the foamed product. Depending on the application processing specifics and the equipment being used to produce the PUR/PIR foam, the rate of manufacture of the foamed product is dependant on the total cure time of the PUR/PIR formulation. It is beneficial to shorten the total cure time, in order to increase commercial output in a given time period.
Conventional catalyst compositions and methods for making foams are described in the following patents and patent applications.
U.S. Pat. No. 4,572,865 describes a method for continuously producing an insulation board comprising a rigid plastic foam core having two major surfaces and a facing material on one or both of the major surfaces, the method including conveying a facing material along a production line, depositing a partially expanded froth foam of a plastic mixture, which contains at least one frothing agent, on the facing material, and further expanding and curing the froth foam in contact with the facing material to form the insulation board.
U.S. Pat. No. 4,710,521 describes a method whereby rigid polyisocyanurate foams are prepared by (a) bringing together on a continuously advancing conveyor an organic polyisocyanate, a minor amount of a polyester polyol, a blowing agent, and, in an organic solvent, a catalyst mixture comprising: (i) a salt of a low molecular weight carboxylic acid selected from the group consisting of an alkali metal salt and an alkaline earth metal salt and mixtures thereof, and (ii) a tertiary amine, the amount of the salt of the low molecular weight carboxylic acid being sufficient and the molecular weight of the carboxylic acid of the salt being sufficiently low to provide a firm foam having a non-friable surface and (b) foaming the foam forming mixture.
U.S. Pat. No. 3,892,687 describes catalysts having a formula for the production of polyurethane resins.
U.S. Pat. No. 3,993,652 describes catalysts that, when prepared in the absence of water, are stable to heat and storage and show high activity in reactions involving organic isocyanates, such as in the production of polyurethane and polyisocyanurate resins.
U.S. Pat. No. 2007/0,259,773 provides trimerization catalyst compositions and methods to produce a polyisocyanurate/polyurethane (PIR/PUR) foam using such trimerization catalyst compostions. The catalyst composition is the product of at least one alpha-beta unsaturated carboxylate salt and at least one second carboxylate salt.
U.S. Pat. No. 2007/0,259,982 provides trimerization catalyst compositions having an alpha-beta unsaturated carboxylate salt and methods to produce a polyisocyanurate/polyurethane foam using such trimerization catalyst compositions.
U.S. Pat. No. 2007/0,259,983 provides trimerization catalyst compositions having a sterically hindered carboxylate salt and methods to produce a polyisocyanurate/polyurethane (PIR/PUR) foam using such trimerization catalyst compositions.
U.S. Pat. No. 6,825,238 relates to rigid foams formed by the catalytic reaction of an aromatic polyisocyanate, a polyols, and a blowing agent and a process for preparing such polyisocyanate.
The previously identified patents and patent applications are hereby incorporated by reference.